Flow

So, how much flow is too much? I've seen several people state their flow rates and 100x, 140x times seems pretty good, but is their a point that is just too much? I know that my mushrooms and my bubble aren't big fans of the flow, but I'm just kind of curious if I put a new pump in to the system where I should stop at? Bigger is better right? Right? More beef, More Horsepower!!!
GRRRR!!